In a manufacturing process for an electric device and a process for plating with a noble metal, waste fluid of cleaning liquid for a product may include a noble metal, and the waste fluid is discarded. In view of economic efficiency and environmental conservation, it is required to recover the noble metal in the waste fluid.
Conventionally, a method for recovering the noble metal is, for example, a method with using active charcoal, an ion exchanging method, or a solvent extraction method. The method with using active charcoal and an ion exchanging method have difficulty with poor selectivity with respect to the noble metal. The solvent extraction method is only applicable for a solution with comparatively high concentration. Further, the extraction solvent soluble in water. Accordingly, environmental load is large. Further, a cost for processing waste fluid of the extraction solvent is high.
JP-A-564-15133 teaches an adsorption agent for noble metal, which is dry powder having a diameter in a range between 150 micrometers and 300 micrometers. The dry power is made from blue-green algaee (i.e., cyanobacteria), red algaee (i.e., rhodophyte), brown algaee (i.e., phaeophytes), dinoflagellata or green algaee (i.e., chlorophyta). Gold, silver and platinum in solution are adsorbed on the adsorption agent, and then, gold, silver and platinum are recovered.
However, in the above recovering method, multiple noble metals are mixed, and therefore, the mixed noble metals are recovered. Thus, it is difficult to separate and recover a specific noble metal from other noble metals.